Gear-grinding machine



July 9, l929- c. H. scHuRR GEAR GRINDING MACHINE Filed Aug. 14, 1925 8 'Sheets-Sheet INVENTOR S/CAA/VU BY July 99 1929. c. H. scHURR GEAR GRINDING MACHINE Filed Aug. 1.4, 1925 8 Sheets-Shel#l 2 lNvENToR @M/o 7L( www #Q A ToRNEYs Filed Aug. 14, 1925 8 Sheets-Sheet .www

INVENTOR 34W Hw ATTORNEY s Iuly 99 1929. c. H. scHURR GEAR GRINDING MACHINE Filed Aug. 14, 1925 8 Sheets-Sheet 4 INVENTOR @K/AMM BY W A f 60ML,

oRNEYs.

July 9, 1929. c. H. scHURR 1,720,404

GEAR GRINDING MACHINE Filed Aug. 14, 1925 8 Sheets-Sheet 5 `INVENTOR #f4 ATTORNEYS July 9, 1929, Q H, SCHURR 1.720.404

GEAR GRINDING MACHINE Filed Aug. 14, 1925 8 Sheets-Sheet 6 L mdm im lNVENTOR p/MW#- ATTORNEYS July 9, 1929.

c. H. scr-"JRR 1.720.404

GEAR GRINDING MACHINE Filed Aug. 14, 1925 8 Sheets-Sheet 7 V sf iw y k v T- EW 5 l QA; ATTORNEYS July 9, 1929. c. H. SCHURR 1.720.404

GEAR @BINDING MACHINE Filed M1514,4 1925 s sheets-sheet a I l I I`/ lNvENToR 94 wan/fo RNEYS I Patented July 9, 1929.

UNITED STA Tes ` CHARLES H. SCHURR, OF CLEVELAND, OHIO, ASSIGNOR TO THE LEES-BRADNER COM- PANY, F CLEVELAND,'OHIO, A CORPORATION OF OHIO.

GEAR-Gambino MACHINE Application mea August i4, 1925. seriai no. 50,239.

rl`his invention relates to an apparatus for grinding or cutting teeth or tooth. faces of gears, for example, gears having teeth generated according to the involute system.-

An o'bject of my invention is to providea machine oi the type mentioned wherein formed gears may be very accurately finished by grinding.

'Another bject of my invention is to provide for thesuccessive grinding of a plurality of formed gear teeth in a very efficient manner.

Another object of my invention `is to provide a machine of the above character which may be stopped automatically at any predetermined point of the grinding operation.

Another object of -my invention is to provide improved tool dressing means for a grinding machine of the above character whereby the grinding tool may be automatlcally dressed at intervals during the grinding operation. n

Another object of my invention is to provide a machine of the type mentioned wherein certain mechanism is employed to impart a rollingmotion to the work as the work carriage is reciprocated.

Other objects and advantages will become apparent as the description of anembodimem of my invention progresses, reference being made to the accompanying drawings forming a part of the specification and in which like characters are employed to designate like parts throughout the same.

In the drawings 1 Fig. 1 is a front elevation of my improved gear grinding machine, showing the tool dressing mechanism and means for operating the same;

Fig. 2 is a rear elevation of my invention :bowing the gear indexing mechanism partly in section;

Fig. 3 is an enlarged front elevation of a portion of my machine, partly in section and taken on line 3-3 of Fig. 1 illustrating the means for moving the work carriage;

Fig. `iis an enlarged horizontal section taken on linee-4 of Fig. 1 and Fig. 7

Fig. 5 is a fragmentary section taken on line 5-5 of Fig. 3 and Fig. 4;

Fig. 6 is a section taken on line 6 6 of Fig. 5;

Fig.7 is an enlarged elevation of the clutch timing mechanism; see also Figs. 4, 10, 11 and 12;

Fig. 8 is a section on line 8-8 ot Fig. 7, but showing the parts shifted in different position than sho'wn in Fig. 4;

Fig. 9 is an enlarged vertical section online 9-9 of Fig. 2;

Fig. l0 is a sect-ion on line 10-1O of Figs. 1 and 7 but to larger scale than Fig. l and smaller scale than Fig. 7;

Fig. 11 is section on line 11--11 of Figs. 1 and 4;

Fig. 12 is a section on line 12-12 of Figs. 1. 4 and 7 s t Fig. 13 is an enlarged section on line 13-13 o-t` Fig. 1;

Figlel is an enlarged axial section through the tool and shaft assembly;

Fig. 15 is an enlarged section on line 15--15 of Fig. 1;

Fig. 16 is an enlarged section on line 16-16 of Figs. 1 and 14; and v Fig. 17 is a vertical section of certain elements taken on line 17-17 of Figs. 4 and 8. A

In the drawings, I provide a base 1 which includes a main supporting frame 2 and a housing This housing encloses the drive Jfor the carriage shitting mechanism, control clutches and other mechanism which will be described more fully as the present description progresses.

Power for driving the apparatus may be derived from power shaiting such as is usually found in machine shops or may be applied directly by connecting a. motor, or the like, to the drive shaft of the apparatus. I. prefer to take power' from a driven pulley by means ot' a belt (not'shown) which drives pulley 4, shaft 5 and pulley 6 on one end of the shaft, and pulley 7 on the other end of the shaft 5. An idler pulley (5 may be provided to take the power` belt if so desired.

A belt 8, or the like, connects the driven pulley 7 with a pulley 9 keyed to .shaft 10 whereupon power is applied to revolve shaft and the pinion 11 which is keyed to shaft 12 through a suitable clutch mechanism. A clutch collar 13 having teeth 14.' is slidably keyed to shaft 1() and when moved to engagement with the pinion 1l having similar clutch teeth 14, will transmit power to rotate shaft 12. The collar is actuated by a crank which is keyed to turn a shaft 16 and to rock a forked member 17 (see Fig. 12) which is provided with blocks 18 pivotally mounted therein to slide the collar 13 along shaft 10. By turning the crank in a clockwise direction the clutch -is disengaged and power is cut olf Jfrom the machine beyond this point. and '12 are. in alignment and their adjacent endstele'scope'as at 19.

The shaft 12 is mounted in suitable bearings consisting at one end of a clutch sleeve member rotatably carried in a bearing support 26 formed within the housing, and atthe other end .an'axial bearing seat 27 formed in the end of shaft 28. .Shaft 28 is rotatably support-ed by the housing at one end and a bearing support 29 at the other end.

s A' suit-able 4power clutch mechanism including a sleeve 30 slidably keyed to the shaft 12 gmu'lfanammly applies power to a wheel dressinfr mechanism at predetermined interv als and relieves the power connection to the work carriage as will be described. Thus while the wheel or tool 31 is being dressed the work carriage may be locked stationary with the work out of engagement with the wheel for a predetermined number of dressing operations. The sleeve 30 is slidable on the shaft 12 and rotates with it, and is provided with an annular rim 32 which engages a notch 34 vformed in the sliding bar 33. This bar is slidable within aligned openings or bearingsformed in the supports 26 and 29 and is provided with notches and 36. Clutch plates or` notch engaging surfaces 37 and 38 are formed integrally on shaft 28 and sleeve 25, respectively, and are each provided with radial openings (not shown), the edges of which are adapted to engage on'e of the adjacent edges of the notches 35 or 36, respectively. according to the position of the sleeve 30. From. description to follow` later herein, it will be seen, thatv when the bar 33 is in the position shown in Fig. 4, the periphery of the plate 38 will register with the notch 36 and will be free to rotate therein, thus rotating the sleeve 25 and the gear 2O to operate the dressing mechanism and disengaging the power connection to shaft 28, but when the sleeve 30 is in its other extreme position, that is, to the left in Fig. 4, the bar 33 will have been moved so that the notch 35 will register lwith the periphery of pl ate 37 while the notch 36 will have assumed a position out of alignment with the plate 38 whereby the radial edge. of said plate will engage the edge of the notch 36. In this position power will he disengaged from the dressing mechanism and will be transmitted from shaft 12 through the clutch mechanism to rotate the shaft 28. The sleeve 30 is provided with plate engaging clutch surfaces at 39 and 40 which engage the faces of the plates 37 and 3S, respectively, when the sleeve is moved -to one. of the positions just described. A radially projecting linger 41 having beveled walls is formed on the sleeve 30, which engage with similar beveled surfaces formed in the clutch oper-V ating bars 42 and 43. These bars are slidably mounted Within the casing Band are similar Shafts to each other except. that the forward contacting surfaces thereof are oppositelv beveled. Each of the bars is provided wit 1 a centrally and oppositely disposed rack section 44 with which a pinion 45 is in mesh so that rotation of the pinion will slide the bars in `opposite directions. As shown in Fig. 17, the pinion 45 is formed on one end of a shaft and a similar pinion'47 is formed on the other end. A second set of slidable bars 48 and 19 disposed on opposite sides of the Pinion 47 and having teeth thereon in mesh with the pinion, is provided as shown in Fig. 8, and are disposed preferably above the bars 4:2 and 43. The bars 4S and 49 are provided on their outer ends with contact members which are adj ustablewithin the bars 4S and 49 respectively and .have preferably conieally shaped heads 50 and 50', respectively. Adjusting nuts 51 threaded upon the contact members serve to hohl the contact members in adjusted position.

Referring now more particularly to Fig. 4, 'a gear 52 is keyed to rotate with shaft 2.8 and meshes with an idler pinion 53 carried by the casing. A gear 54 is keyed to a. shaft 55 which rotates upon suitable ball or roller bearings 5G. The said gear 54 is removabljv mounted on one end of the shaft heilig held by a nut 54 as shown while to the other end of the shaft is secured a member 57 having a -cam groove 58 formed therein about its pc.-

riphery. Referring to Fig. 3, where I have shown the path of the groove partly by dotted lines, I provide a connecting rod 59 having a groove-'engaging roller 60 adjustably mount* ed on one end to seat within the groove and to follow its path during revolution of the member 57, imparting reciproeatory motion to thc pitman and the work carriage 61 to which the other end of the pitman is adjustably se' cifted at 62. The roller mounting (58 slides along a guide rail or the like G3 formed on the casing to provide for rigidity of operation with a maximum of efliciency.

Referring to Fig. 4 again, it will be noted that the 'member 57 is keyed to the shaft 64 which is a reduced extension of shaft 55 and -"is locked thereon against axial movement by a nut 65. The gear 54 is provided on its inner 'face with a roller engaging trip 66, shown in 'detail in Figs. 5 and 6. This trip extends almost to' the outside diameter of the teeth on the gear and is so positioned on the gear that it engages a roller ("7 carried by one arm of a bell crank 68 which is mounted to rock on the casing. The other arm of the bell crank is connected to suitable plunger operating and associated mechanism by means of a connecting rod '69. 'lhis'mechanism will be described in detail as the present description ofn'iy invention progresses.

A second trip device 70 Consisting more essentially of Va cam surface is formed on the outer face of the gear 54 and is tim'ed to engage and slide the bar 71 outwardly or to the right in Figs. 2 and 6 and to the left in Fig. 4 just after the roller 67 has engaged the outer peripheral surface of the trip 66.

Suitable mechanism for determining the periods over which the clutch generally designated at 30, is operated to alternately connect the source of power to the tool dressing mechanism and to mechanism for rcciprocating the carriage and operating other mechanism associated therewith, is provided in the forward portion of the casing and is shown partly in detail in Figs. 7 and 12. This mechanism includes a cam 72 which is adjustably secured to a shaft .7 3 by a nut 73 through cone members 73 and is driven by gear 11 and pinion 11 keyed to shaft 73, Fig. 12.

An arm 74 having a vhub 75 is pivotally mounted to rock about a shaft 93.y Fig. 7 and is provided with a roller 76 on its outer lend which engages the periphery of the cam surface 72 of the cam 72 and rides thereover. About midway 'of the arm is pivoted a dogr 77 normally under tension of a spring 78 to cause the dog to engage the teeth 79 of a ratchet or disc 80. The ratchet 80 is keyed to a sleeve 100, Fig. 10, and is rotatable about an axis coincident with the pivot axis of the arm 74 and independently therefrom. A spring 81, Fig. 7, is secured on one end to the arm 74 and at the other end to the casing 3 to normally maintain thevarm roller in contact with the periphery of the cam 72. For each rotation of the cam 72 the dog 77 will advance the ratchet in a counter-clockwise direction the distance of one tooth. A trip plate 82 having pointed projections'or tripping members 83 and 84, Fig. 8, thereon is secured to rotate with the ratchet 80, the tripping membersbeing positioned on the plate to engage the contact members 50 and 50', respectively. The contact members are offset so that the tripping members will strike only their respective Contact during rota-tion of the ratchet 80. A second trip device 85 is secured to rotate with the ratchet and has an inclined arm engaging surface 86 which is adapted to engage the arm 87 pivoted to the casing at 88. Rocking of the arm to the right, as in Fig. 7, will operate the power clutch collar 13 through the connecting rod 89, crank 90 and shaft 16, tc sever the power connection from the machine beyond the clutch 13.

A sleeve 91 carrying a trip bearing member 92 is mounted to be rotated coaxially with but independently of the ratchet 80 when desired and its outer peripheral end carries trips 94 and 95. This sleeve being keyed to the shaft 93 is free to be set at any desired point about its axis of rotation and this is accomplished by providing a dial 96 keyed to the other end of the shaft 93 and having clutch teeth 93 adapted to cooperate with similar clutch teeth formed on a collar 99. A

ring 97 may have markings thereon and is provided with a seat 97 on its inner side face which receives a spring pressed ball 98 mounted in the :trame 3 when the ring is rotated to zero position to normally hold and indicate that the ring is in its zero setting position. A set screw 99 is provided to lock the ring to the collar 99. The collar 99 is intermediate the ring 97 and the dial 96 and may have indicating markings thereon. This collar is keyed to sleeve 100 to rotate therewith and is provided with an annular groove to seat a spring 101. The spring normally is under compression between the members 96 and 99 and serves to separate said members when the nut 100 is uuscrewed. By the use of thc mechanism just described and shown in enlarged detail in Fig. 10, the operator of the machine is enabled to select a setting of the dia-l 96 whereby the member 92 is rotated so that its trips 95 and 94 are spaced from the trips 83 and 84, respectively, of the ratchet 80. The distance between the trips thus selected is equal to a given number of teeth of the ratchet and corresponds to the number of teeth to be ground on the blank. A more detailed description of the operation ol' the selecting mechanism will be given when the operation of the entire machine is described.

Suitable-mechanism for imparting a rolling movement to the gear blank as the car riagc, on which it is mounted, is reciprocated, is provided and operates in conjunction with a mechanism for indexing the blank. The indexing mechanism includes a bar 71 previously describedas being reciprocatedby having its one end engaged by the trip 70 in the casing. A rod 103 slidable within suitable bearings 104 in a casing 105 is provided with a substantially central depressed rack portion 106 therein which is engaged bythe teeth of a pinion 107 on a shaft 108. The one end of the rod 103 abuts the free end of the bar 7l as shown in Fig. 2. A retracting spring 109 is secured to the rod 103 and adjustably fastened to the casing and normally pulls the rod to the left. The pinion 107 is mounted in suitable bearings and keyed to its shaft to rotate therewith is a larger pinion 110 which meshes with a freely rotatable gear 111. This gear 111 is provided with an annular iange on one side and keyed thereto is a ring 112 having a. dog 113 pivotally mounted thereon for engagement with an adjustable shield 114 over which it rides when out of engagement with a ratchet 115. The dog 113 is loosely pivoted to the ring 112 and during movement of the gear 112 rides over the edge of the shield and engages the teeth of the indexing ratchet 115 which is keyed to the main spindle 116. Engagement of the dog with the ratchet 115 and. further movement of the ring 112 will therefore cause the spindle 116I to be llO . rotated. As the ring 112 is rotated in the opposite direction, the dog is made to disengage the ratchet 115 and again ride over the shield. The shield is shiftable about the ratchet 115 so that its position determines the number of teeth on ratchet 115 which are to be engaged by the dog thereby shifting the gear blank on the end of thespindle the distance corresponding tp the number of teeth engaged by the dog. Suitable securing means at 117 maintain the ratchet 115 locked on the spindle.

It will be noted that 1 have provided a bearing 118 between the fra-me 119 and the gear 111 so that ree movement of the gear 111 upon the spindle and frame is permitted. By providing a bar 71 which is removable from the casing 3, I may very readily disengage the automatic means for operating the indexing inechanismby simply removing said bar. The blank may then be indexed by hand 'if desired.

The main spindle 11G is provided witha central opening running longitudinally thereof.' but ot' different bores at the ends thereof.

.'1` he walls of the opening are tapered slightly at each end as shown in Fig. 9. A spindle 12,0 being tapered to snugly fit the walls of the opening at the rear end, as shown in the figure, is provided with a removable gear 121 keyed to its free end, a nut or other fastening means 121 being employed to preventaccidental displacement of the gear and to pro'- vide for interchanging gears of different sizes according to the size ot' the blank to be ground. A spindle 122 having tapered walls to snugly seat. within the tapered opening at the other end ot the main spindle exten-tls outwardly thercf rom, its outer end being provided with converging walls and terminating in a blank holding end 123. A blank 12/1 is shown secured on the end of the spindle by a nut or the like 125. A rod 126 is threaded at one end within the spindle-122 and passes axially through the spindle 120. Its free end is provided with a shouldered portion 127 having an inner cone surface for seating within the end ot spindle 120. By applying a wrench to the. shouldered end and turning the spindles are drawn together and locked within the main spindle 116 by virtue of the tapered walls. 'The main spindle 116 is rotatably mounted within the carriage 61 and hasa collar 128 secured thereto and abutting a bearing sleeve 129 keyed to the spindle 116. A suitable bearing consisting of plates 130 and spaced balls or rollers 131 engages the other end of the sleeve and a spring 132. This spring normally exerts a pressure against the outer bearing plate and maintains the spindle seated within the casing in the proper position and prevents outward axial movement thereof. A shield 133 is provided tQ rotate with the spindle to prevent the entrance of bits of metal ground from the blank into the ing a bar or the interior of the spindle and damaging -the bearing surfaces.

Suitable means for rol-ling the blank and spindle, engage gear 121 on the rear end ot' the spindle 120, and consist of two rack bars '134 7o and 135 arranged in parallel relation with the teeth of one bar sli fhtly offsetting the teeth of the other bar. gpon reciprocating the carriage 6l, the 'gear 121 will roll along the racks and will impart such rolling motion to the blank through the spindle. As has been described, the rack bars are so placed` that their teeth are slightly offset with respect to each other and when they are brought into engagement with the gear 121, the slightly offset teeth will readjust themselves to insure a pertect'rneshing with the teeth of the gear 121. The bar 135 is preferably rigidly secured to the plunger 136 while the bar 134; is slidably mounted therein. The bar 134 is 85 normally forced to the left in Fig. 2 by an adjustable spring held within a casing 136. Thus whenthe gear 121 is out 'of engagement with the rack bars, the spring will cause bar 134 tomove to the let and will cause the 90 teeth of the respective bars to be slightly olfset with respect to each other. When the gear 121 is in engagement with the bars, bar 134 will provide a means for preventing back lash in the gear 121.

The plunger 136 reciprocates vertically within a easing 137 and its lower end is provided with a plate'138 and a nut-139 for securing the plate to the plunger. A bushing having a flanged edge 140 is mounted in the 100 casing 14H-while the plate 138 seats against the flange 140 as shown in Fig. 9.- A cover plate 141 is secured by bolts or the like to the casing' 137. The casing 141 is rovided with'extended guiding edges 142 at its lower 105 enel. The upper end of the casing likewise carries a bushing 143 which is in alignment with the bushing 140 and the plunger is movable therein.

Suitable means ot adjusting the limits o the plunger movement when larger or smaller blanks are to be ground, has been shown in the form of providing means for adjusting' the plunger casing 141 consisting of adjusting screws 161. By loosening the screws and breaking the connection through the cone clutch nembers 152 and 154 by loosening the nut 155, the casing 141 may be shifted vertically up or down as desired until the correct adjustment is reached for the particular size gear being ground. Vertical movement of the casing 141 is aecomplishedby insertlike in holes formed radially in the member 154 and applying force to the bar to rotate the member 154 which will 125 cause thegear to rotate to raise or lower the plunger. Then the screws 161 and nut 155 are tightened to maintain the casing in the desiredadjusted position and to re-establish the connection through the cone clutch.

lleeth 144 are formed on the rear face of the plunger for a portion of its length and f engage the teeth formed on the gear 145. 'l`he Connecting rod 69, which is pivotally connected at. one end to the member 68 and is reciprocated thereby, is connected at its lower end to a g1ar 146 rotatably mounted on a shat't 147. The gear 146 is provided with teeth partially around its periphery and meshes with a gear 148. A toothed clutch 150 having one member carried byl the gear 148 is provided, and transmits power from. the gear through a shaft 151 having a reduced end 153 and a male cone clutch member 152 on its opposite end. The reduced shaft end 153 is disposed axially within a sleeve 153. A female cone clutch member 154 which eooperates with the male clutch member 152 is carried on the outer end of the sleeve, and a nut 155 is provided for locking the sleeve and shaft against relative movement. A gear 145 is keyed to the other end of sleeve 153 and meshes with the rack teeth 144 to raise and lower the plunger and thereby engage and disengage respectively the bars 134 and 135 with the gear 121. An arm 157 is rockable with the gear 148 and a spring 158 for normally maintaining the rack 134-135 in engagement with the gear 121 when the plunger tripping mechanism is inoperative is attached at one end to thearm and at its other end to a pin or the like 159 carried by the main trame. When the trip is actuated, the plunger is moved downwardly and the spring 158 is placed under tension, and when the roller 67 leaves the trip 66 the rod 69 is moved downwardly, power will be transmitted through gears 146 and 148 ,and through the cone clutch 152 and 154 to the gear 145 and plunger 136, moving the'latter upwardly and bringing the bars 134-135 into the path ofmovement of the gear 121.

Referring now to Figs. 1, 4, 11, 13 and 15, 1 will describe the mechanism for performing the dressing operations.

1n Fig. 4 1 have shown how the power is taken from the main driving parts within the casing. As the shaft 22 mounted in sleeve 23 andthe helical gear 21 rotate, bevel gears 24 and shaft 170 are also caused to rotate and transmit power through the universal coupling 171 and shaft 172 and through helical gears 173 and 174 to a shaft 175 mounted in suitable bearings 17 6 in a casing 177 (Fig. 13

i4 cam plate 178 is secured to rotate with ,shaft175, by a nut 179 and is provided with a 'lV-slot running around one face as shown in Fig-..15 at 180. Cam members 181 and 182 are adjustably carried by the plate 178 and are secured thereto by means ot nuts 184 and headed fasteners which are carried within the slot 180. 1t is apparent therefore that these cam pieces may be adjusted in spaced i uor contacting relation upon the plate. .A1-

though 1 have shown but two cam members on the plate 1 may use a greater number since each cam surface positively operates the dressing tool and by using a given number of cams I am able to dress the'wheel a given number of times during the dressing operation. I may use only one cam and thereby limit the dressingr operation to but one contact between the tool and the wheel. As shown in Fig. 1` 1 have provided cam members 181 and 182, the former having cam surfaces-at such an angle to the base of the cam that it will cause the tool to move quickly over the working edge of the tool 31 while the latter cam will be provided with cam surfaces of more gradual rise and fall so that when this cam comes into operative position for moving the tool to dress the wheel the movement of the tool will be slower than the former movement. The result obtained is that the first cam provides for a quick or rough dressing ofthe wheel while the latter cam provides for a more gradual or finish dressing of the wheel. As pointed out above 1 may use additional cams, if desired, and these may have surfaces of the same or of varied inclinations. It is also to be understood that I may space the cams to any desired position on the plate to provide for an interval between the rough and finish dressing operations. Keyed to a dressing tool operating shaft 185 is an arm 180 having a cam engaging roller 187 mounted on its free end. The shaft 185 is rockable in suitable bearing and keyed to it is an arm 188 carrying at its outer end a link 192, connecting to the bell crank 191. An adjustment device for regulating the swing of the tool, when the shaft 185 is rocked is carried by an arm 193 which is keyed to the ,shaft 185. This adjustment device consists of a thumb screw 189 having a central longitudinal threaded opening. A threaded member 190 is adjustable within the openingr and is swivellv secured to one arm ot a crank 191 which is rotatably mounted on the dressing tool carrying shaft 185'.

A spring 195 is attached at one end to the arm 188 and to the easing 196 at the other end for normally maintaining the roller 187 in position to contact with the cams on the plate 178 as they are rotated into contacting position. A trip 197 is secured to the plate 178 in a manner similar to the cams 181 and 182 and is so positioned on the plate that it contacts with a trip rod 198 to operate suitable tool advancing mechanism. r1`he rod 198 is provided on its trip engaging end with a suitable engaging nose 198 for the trip 197. The other end of the rod is connected through a swivel 199 and a link 200 to a plate 201 which is loosely mounted on the vhub of a ratchet 202 which is keyed to the shaft 203 and carries a pawl 203 engaging ratchet 202 keyed to the shaft 203. A hand wheel 204 is also keyed to the shaft 203 tor manually adjusting the 208 and may be secured in various positions` about the ratchet 202 to limit the numberl of teeth engaged by the pawl 203 during its movement and consequently regulatingthe advance `of the tool. It will be seen, therefore, that I have provided for both manuall and automatic operation of the tool advancing mechanism. A Worm 205 is also keyed to shaft 203 at the other end thereof, being secured thereto by a nut 205', and meshes with a worm gear 206.

Referring now more particularly to Fig. 14, I have shown the Worm 205 and tbe Worm gear 206, the latter being internally threaded as at 207. A suitable casing 196 forms bearing surfaces for the Worm gear and also is eX- tended toward the rear as at 209 to'provide Y. a housing for the drive pulley 210 which is rotatably mounted in suitable bearings 211 and is keyed to the reduced'end of the tool spindle 212. Connection to the power source for rotating the tool is made by means of a belt or the like 210 running over the pulley .210 through an opening in the frame of the machine and over suitable belt tightening idlers to the drive pulley 6. Keyed to the spindle 212 is a sleeve 213 having a shoulder 214 formed on one end and secured against longitudinal movement to the right in Fig. 14 by a nut 215. The sleeve 213 is held toward the right in Fig. 14 by a compression spring' 216 one end of which abuts against the shoulder 214 on the sleeve. The other end of the spring 216 abuts upon one face of an annular ball bearing 217, thev other face of which abut-s, as shown in Fig. 14, upon an internal shoulder of the sleeve 218. By this means, since the spindle 212 is keyed to the sleeve 213, the spindle is resiliently held axially toward the right in Fig. 14 and its position determined by a flange 217" on the spindle thrusting upon a Washer 218', and the latter thrusting upon the end of the sleeve 218. Since the greater part .of the length of the spindle 212 extends to the right of the Washer 218', and since the Working planular face 241 of the grinding Wheel 31 which is mounted on the spindle 212', as Will be described, lies approximately in the plane of the Washer 218. the lengthwise contraction and expansion of the spindle 212due to change of temperature tvill not materially move the position of the tool 3,1 and will permit its AWorking face 241 to be accurately maintained in a predetermined position. The sleeve 218 is movable longitudinally Within the casing 196 by means of the internally threaded Worm gear 206 and threads 221 on the sleeve, and is provided with a longitudinal slot 219wvhich registers with the set screw 220 which prevents circumferential movement but allows longitudinal movement of the sleevev 218. The movement of the sleeve longitudinally is very slight since such movement depends upon the'rotation of worm gear 206 Whose internal threads are in mesh with the threads 221 on the end of the sleeve 218. A tapered bushing 222 is interposed between the sleeves 213 and 218. A plate 223 is bolted to the end of sleeve 218. This plate has an opening through which the spindle is free to rotate and is also provided with an annular ilange 224 for engaging the enlarged end of the bushing and preventing its movement to the right in Fig. 14.

At the free end of the spindle I have provided a grinding Wheel supporting member 225 having a tapered hub keyed to the tapered endof the shaft 212 and having an annular seat formed therein vfor the reception of a grinding tool or Wheel 31.

A clamping member 226 is adapted to lit over the outer end of the member 225 for clamping the Wheel 31 on the supporting member A nut 228 threaded on the member 225 and engaging the member 226 securely holds the tivo members and tool`31 in clamped position. A nutr229 is provided on the end of the spindle to permit removal of the clamping member 225. t

Referring now to Fig. 1, it will be seen that I have mounted the grinding Wheel assembly and dressing mechanism on a plate 230. This plate is carried on a frame 231 and is Capable of a substantially vertical adjustment with respect thereto. Bolts 232 are provided to lock the plate in the desired adjustment on the frame. The frame 231 is capable of angular adjustment with respect to the main frame 2 by virtue of the elongated slots 233 and securing bolts 234. An adjusting sere7 235 is threaded into the support 236 and pas'sd into a suitable opening in the plete 236. A gear 237 keyed to the screw 235 is engaged by a gear 238 keyed to a shaft having a squared end 239. A crank (not shown) may be placed upon the squared end of the shaft for'turning the same for making vertical adjustments of the tool 31.

It Willbe'noted that I have provided an opening in the Wheel casing 194. This opening has one of its edges 240 in the Working plane of the tool 31, that is, in the same plane as the planular face 241 of the tool. It is the purpose of this edge to serve as a guide in setting the diamond dressing tool 242 after inserting a new tool or after the oldone has been Worn considerably. By placing the cutting edge of the diamond .point against the edge 240 of the casing and then tightening ythe adjusting nuts 243 the tool Will be in correct cutting position for dressing the Wheel grinding surface. It Will also be noted that the dressing tool mounting 244 is adjustably carried in a holder 245 which is keyed to the shaft 185. Rocking of the shaft by mechanism hereinbefore described will rock the tool holder and diamond point 242 across the to rotate.

working face 9.41 of the tool 31 for dressing the latter, the dressing periods and quality of dressing being controlled by apparatus hcreinbefore described.

I will now briefly and more generally describe the operation 4ot' the machine with a view to more clearly pointing out how the various operations are performed and cooperate with each other to contribute to the ultimate purposes and objects of the machine in turning out completed work of a high degree ot' accuracy and quality.

- As power is applied to the pulleys 6 and 7, the grinding wheel or other tool Slis caused Power is coupled through the clutch mechanism, shown generally at 13 and 'manually operable byA acrank 15, to a carriage driving and other mechanism within the`casing 3.

A second clutch mechanism indicated generally at 30 and associated parts is operable to couple the tool dressing mechanism with the drive through clutch 13 or to shift the power directly through from the clutch 13 to the carriage reciprocating mechanism, the indexing mechanism and the mechanism for imparting a rolling movement to the blank. As-the clutch 30 is shifted from one position to another, it will cause the power to be shifted to either one or the other of its associated mechanisms. The clutch 30, therefore, serves to permit of a dressing operation, while the carriage and other associated mechanism is idle.

The mechanism carried within the casing 3 and shown in detail in Figs. 7 and 8 is provided for controlling the movement of the clutch 30. When it is desired to grind a gear blank having, for example, twenty teeththereon, the clutch may be so timed to connect the power source to the lcarriage and other associated mechanism until a given number of teeth'have been ground and then interposing a period when the dressing mechanism is operative. A second period of grinding and a final period of dressing complete the cycle of operation of the timing mechanism, since at the completion of the last dressing period the source of power is caused to be disconnected from the machine .by the shifting of clutch 13 by the trip 85. The timing of the clutch 30 is accomplished by first setting the ring 97 until the seat 97 therein is engaged by the ball 98. This will indicate a zero position or a point from which-to count in determining the point at which the dress mechanism is brought into operation. In setting the clutch controlling apparatus the nut 100 is first loosened until the spring 101 forces the member 96 outwardly free. of the member 99. 'While in this position, the member 96'is rotated in one direction until its reading indicates that the shaft 93 and arm 92 have been rotated a distance equivalent t-otwenty teeth, on the ratchet 80. It will to operate.

be noted that during this step the ratchet 80 and-arm 92 are relatively movable and the trips 9st and 95 have been spaced from trips 83 and 84 respectively, a distance equivalent to twenty teeth on the ratchet 80 since in this particular instance I am describing the grinding of a blank having twenty teeth.

It will be seen that the trips 9i and 95 are fixed relative to each other,'as are also the trips 83 and 84. The distance between the trips of the respective sets 94-95 and 83^81 represents the. period through which the dressing mechanism is in Connection with the source of power through the `clutch 30. I find that the trips-of each set may be lixed in spaced relation a distance of .qiproximately three ratchet teeth, although any other distance between the trips providing for a great er or shorter dressing period may be utilized, if desired.

After the members 9G' and 99 have been brought to the proper setting as above described, the nut 100 is screwed in again, locking the members together. IVhen the member 96 is now turned, rotation of shaft 93, arm 92, member 99, sleeve 100 and ratchet 80 is also accomplished. Rotation of member 96 to the right will therefore cause the movement of the trips 94, 95, 83 and 84C now in locked spaced relation to be shifted to the right in F ig. 7 `When grinding a blank having twenty teeth the members 96 and 99 are rotated to the right so that the zero point on the ring 97 is now set a distance to the right of a fixed zero mark on the casing 3, equivalent to twenty teeth on the ratchet 80. It will be observed then that the setting is now complete and that upon shifting the clutch 13 so that the source of power is applied to set the machine into operation, the `ratchet will be rotated step by step to the left in Fig. 7 by virtue of the cam 72 and dog 77 and other associated mechanism.

As the rotation of the ratchet and -other parts progresses, the trip 94 will engage the contact member 50 and cause the clutchBO to disengage the carriage shifting and other sociatcd mechanism which has been operating upto this point, and to immediately engage the tool dressing mechanism to cause it The dressing mechanism operates until the trip 95 engages thc contact member 50 4when the dressing mechanism will be disconnected from the power source by virtue of the shifting of clutch 30 out of engagement with the dressing mechanism and immediate- 1y into re-engagement with the carriage and other mechanism for the second grinding operation. This grinding operation continues until the ratchet has been advanced a distance equivalent to twenty teeth thereon when the trip 83 engages the contact member 50 Where; upon the dressing mechanism is again caused to operate while the carriage mechanism' "is locked in idle position. This second dressing operation continues until the trip 84 engages the contact member 50.

At the completion of the second dressing operation or when the trip 84 engages the 'member 5.0 the trip 85 simultaneously engages the arm 87 and through other suitable mechanism causes the shaft 16 to be rocked and the power clutch 13 to be automatically disengaged from the power source, stopping the machine. It will be noted that the ratchet 80 is advanced to the -left in Fig. 7 the distance of one of its teeth for each complete reciprocation of the carriage 61, and that the carriage is only movable when the clutch 30 is engaged with the carriage operating mechanism and disengaged from the dressing mechanism.

The blank may now be removed from the spindle and reversed so that the opposite tooth faces may be ground.

The indexing mechanism, the carriage reciprocating mechanisn'x and the mechanism for imparting a rolling movement tothe blank are all operated by mechanism connected to the clutch 30, so that when the clutch 30 is in position to transmit power through to such mechanism, it is disengaged from the dress-y 'engagement with the gear 121 which is keyed to the rear end of the blank carrying spindle. W'hile the gear 121 is thus disengaged the indexing mechanism is caused to operate to advance the blank by rotating the spindle the desired distance. The shield plate 114is adjustable over the gear 115 to permit engagement of the'spindle rolling dog 113 with only the desired number of teeth on the said gear, thus controlling the advancement of the blank at ea ch complete reciprocation of the carriage.

As the carriage begins to move to the right in Fig. 2 mechanism associated with plunger 136 is caused to move the' plunger upwardly so that the racks 134; and 135 are brought into the path of movement with the-gear 121.- v As the carriage continues to move to the right, the gear is caused to rollV along the rack and to Vimpart such rollinor motion to the blank carried on the other end of the spindle. During such rolling movement of the blank, the blank is caused to move in the working path of the tool31 and the teeth of the blank are subjected to the action of such tool. Although I prefer to use a grinding tool, I may use any cutting or other tool if desired. The return movement of the carriage will cause the blank to be rolled in the opposite direction and as the carriage approaches the left in Fig. 2, the cycle of operations is repeated.'

The number of reciprocations of the carriage and consequently the indexing of the blank is controlled by the mechanism already described and shown more particularly in Figs'. 7, 8 and l0. After a predetermined number of cutting or grinding operations has been completed, the clutch 30 is automatically shifted to c nnect the power source to the dressing mec ianism which causes the tool 31 4to be subjected to a rough and a finish dress of the construction and operation of my machine that I have provided an apparatus which will produce finished gears and the like very etciently and accurately.

Having thus described my invention I am aware that numerous and extensive changes may be made from-the embodiment herein described and claimed, but without departing from the spirit of my invention or the scope of the subjoined claims.

I claim 1. In amachine of the class described, the

combination of a base, a'carriage movable thereon, a spindle rotatably carried by said carriage, a blank carried by said spindle and rotatable therewith, a tool disposed in the path of movement of said blank, indexing means to advance said blank when said carriage has reached a predetermined position on said base, means for imparting a rolling movement to said blank during the-movement of said carriage, said last named means including a rack and a gear carried'b said spindle and adapted-to roll along sai rack during the movement of said carriage, and mechanism operable to move said rack into and out of the path of travel of said gear.

2. In a machine of the class described, the combination of a base, a carriage movable thereon, a spindle rotatably carried by said carriage, a blankcarried by said spindle and rotatable therewith, a tool disposed in the path of movement of said blank, indexing means for advancing said blank when said carriage has reached a predetermined position on said base, means for imparting a rolling movement to said blank during the movement of said carriage, said last named means including a rack and a' gear carried by said spindle and adapted to roll along said rack during the movement of said carriage, and a plunger carrying said rack thereon and operable to move the rack into and out of the path of travel of said gear.

3. In a machine of the class described, the

insonne combination of a base, a carriage movable thereon, a spindle rotatably carried by said carriage, a blank carried by said spindle and rotatable therewith, a tool disposed in the path of movement of said blank, indexing means to advance said blank when said carriage has reached a predetermined position on said base, and means for imparting a rolling movement to said blank during the movement of said carriage, said last named means including a rack and a gear carried by said spindle and adapted to roll alongsaid rack during the movement ot' said carriage, and a plunger carrying said rack thereon and operable to move it into and out of the path of travel of said gear, said rack consisting of teeth relatively movable and normally slightlyout of alignment when not engaged by said gear.

4. ln a machine of the class described, the combination otI a base, a carriage movable thereon, a spindle rotatably carried by said carriage, a blank carried by said spindle and rotatable therewith, a tool disposed in the path of movement of said blank, indexing means to advance said blank when said carriage has reached a 4 predetermined position on-said base, and means for imparting a rolling movement to saidblank during the movement of said carriage, said last named means including a rack and a gear carried by said spindle and adapted to roll along said rack vduring the movement of said carriage, and a plunger carrying said rack thereon and oper- -able.to move it into and out of the path of travel ot said gear, said rack consisting of a plurality of longitudinal sections, the teeth of .one section being normally slightly out of alignment with the corresponding teeth of another section when not engaged by said gear.

5. In aI machine of the class described, the combination of a. base, a carriage movable thereon, a spindle rotatably carried by said carriage, a blank carried by said spindle and rotatable therewith, a tool disposed in the path of movement of said blank, indexing means for advancing said blank when said carriage has reached a predetermined position on said base, means for imparting a rolling movement to said blank during the movement of said carriage, said last named means includingr a rack and a gear carried by said spindle and adapted to roll along said rack during the movement of said carriage, and a plunger carrying said rack thereon and operable to move said rack out of the path of travel of said gear just prior to the adfustment ot said blank by said indexing means.

6. ln a machine ot' the class described, the combination of a base, a carriage movable thereon, a spindle rotatably carried by said carriage, a blank carried by said spindle and rotatable therewith, a tool disposed in the path ot movement of said blank, indexing means for advancing said blank when said carriage has reached a predetermined position on said base, means for imparting a rollingmovement to said blank during the movement of said carriage, said last named means including a rack and a gear carried by said Spindle and adapted to roll along said rack during the movement ot said carriage, a trip, and a plunger actuated by said trip and carrying said rack thereon to bring it into the path ot travel of said gear, means for adjusting said plunger vertically rela tive to said base and adjustment compensating means intermediate said trip and said plunger for maintaining an operative connection between said plunger and said trip when the former is adjusted vertically.

7.` In a machine of the class described, the combination of a base, a carriage movable thereon, a spindle rotatably carried by said carriage, a blank carried by said spindle and rotatable therewith, a tool disposed in the path of movement of said blank, indexing means to advance said blank when said carriage has reached a predetermined position on said base, means for imparting a rolling movement to said blank during the movement of said carriage, said last named means including a rack and a gear carried by said spindle and adapted to roll along said rack during the movement of said carriage, a trip, and mechanism intermediate said trip and said rack to bring said rack into the path of travel of said ear.

8. 1n a gear grinding mac ine, a work spindle, a gear on the spindle, a rack, means for rolling the gear on the rack to 've a rolling movement to the spindle, sai rack being movable radially with respect to said gear out of engagement therewith to permit the gear and work spindle to be indexed.

9. In a gear grinding machine, a work spindle, a gear on the spindle, a rack, means for rolling the gear on the rack to give a rolling movement to the spindle, said rack being movable radially with respect to said gear out of engagement therewith to permit the gear and work spindle to be indexed, and indexing means therefor.

10. ln a gear grinding machine, a work spindle, a gear on the spindle, a main rack, means for rolling the gear on the rack to give a rolling movement to the spindle, said rack being movable radially with respect to said gear out of: engagement therewith to permit the gear and work spindle to be indexed, a supplemental rack tor the longitudinally relatively to the main rack whereby1 the teeth of said gear may be held in engagement with the teeth of the main raeltf l1. In a gear grindingl machine, a work spindle, a gear on the spindle, a main rack, means for 'rolling the gear on the rack to gear movable lll) give a rolling movement to the spindle, said rack being movable radially with respect to said gear out of engagement therewith to permit the gear and work spindle to be indexed, a supplemental rack for the gear movable longitudinally relatively to the main rack, resilient means for moving the supplemental rack to cause the teeth of the gear to be held in engagement with the teeth of the main rack.

.12. In a gear grinding machine, a reciprocable carriage, a work spindle rotatably mounted thereon, a gear on the spindle, a rack, means i'or recipro'ating the carriage and tor rolling the gear on the rack to give a rolling movement to the spindle, said rack being movable radially with respect to said gear out of engagement therewith to permit the gear and work spindle to be indexed, and automatic means for so moving the rack at a predetermined point in the reciprocatory movement of the carriage.

13. In a gear grinding machine, a recipro- .cable carriage, a work spindle rotatably mounted thereon, a gear on the spindle, a rack, means for reciprocating the carriage and for rolling the gear on the rack to give a rolling movement to the spindle, said rack being movable radially with respect to said gear out of engagement therewith to permit the gear and work spindle to be indexed, and automatic means for so moving the rack for indexing the gear and spindle and for returning the rack to engaged position with the gear at a predetermined point in the reciprocatory movement of the carriage.

14. In a gear grinding machine, a reciprocable carriage, a work spindle rotatably supported thereon, power actuated means for.

reciprocating the carriage and giving a rolling movement to the work spindle, means for indexing the Work spindle after a predetermined number of reciprocatory movements, automatic means for stopping the reciprocatory movement at the end of a predetermined number ot' reciprocatory and indexing movements and for simultaneously connecting a wheel dresser to the source of power, and automatic means for disconnecting the machine from the source of power to stop it after a predetermined number of reciprocatory and indexing movements.

15. In a machine of the class described, a work spindle, a gear thereon, a'rack, means for rolling the gear on the rack to give a rolling movement to the work spindle, means for withdrawing the rack from the gear by movement in a direction radial with respect to the gear, and for returning the rack into meshed engagement with the gear in indexed relation thereto.

16. In a machine of the class described, a work spindle, a gear thereon a rack, means for rolling the gear on the rac to give a rolling movement to the work spindle, means for withdrawing the rack from the gear by movement in a direction radial with respect to the gear, means for indexing the gear while the rack is withdrawn and for returning the rack into meshed engagement with the gear in indexed relation thereto.

17. In a machine of the class described, a work spindle, a gear thereon, a rack, means for causing relative rolling movement between the gear and rack whereby the spindle is given a rolling movement, means for dis-- engaging the gear and rack by relative movement thereof inga direction radial with respect to the geil' and for re-engaging the gear and rack in indexed relation.

18. In a gear grinding machine in which the gear tooth faces are ground on the planular face of a rotar)Y grinding wheel by relative movement between the gear and wheel, which movement is that ot' the gear rolling on a rack, one tooth face ot' which raclrand the face of the wheel are in a common plane, automatic. power actuated means for maintaining said planular face approximately in said plane within predetermined limits, which includes means for advancing the )lanular face axially at the end of a pre etermined number of tooth face grinding operations and then moving a dressing element on the. planular face in said plane; and means for adj ustably positioning said element so as to move in said plane comprising a reference station on the machine and in said plane toward and from which said element maybe adjusted.

19. In a gear grinding machine in which the gear tooth faces are ground on the planular face'of a rotary grinding wheel by relative movement between the gear and wheel, which movement is that of the gear rolling on a rack', one tooth face of which rack and the face of the wheel are in a common plane, automatic power actuated means for maintainin said planular face approximately in sai plane within predetermined limits, which includes means for advancing the planular face axially at the end of a predetermined number of tooth face grinding operations and then moving a dressing element on the planular face in said plane; and means for adjustably positioning said element so as to move in said plane comprising a reference station on the machine and in said plane toward and from which said element may be adjusted; said machine having also a clutch device adapted to operate automatically at thel end of a predetermined number of grinding operations to disconnect the gear grinding mechanism from the source of power and to simultaneously connect said plane maintaining means thereto.

20. In a machine of the class described, a base, a carriage reciprocable thereon, a work spindle on the carriage adapted to support a gear blank thereon, means for reciprocating the carriage, a tool disposed in the path of `movement of the blank on the carriage, means for indexing said blank with respect to the tool at a predetermined position of the carriage, said means including arack, a pinion meshing therewith, means for moving the rack longitudinally in timed relation to the movement of the carriage, and connections between said pinion andthe work spindle.

21. In a machine of the class described, a base, a carriage i'eciprocable thereon, a work spindle on the carriage adapted to support a gear blank thereon, means for reciprocating the carriage a tool disposed in the path of movement of the blank on the carriage, means for indexing said blank with respect to the tool at a redetermined position of the carriage, said) means including a rack, a pinion meshing therewith, means for moving the rack longitudinally in timed relation to the movement of the carriage, and rotary connections between said pinion and the work spindle.

22. In a machine of the class described, a base, a carriage reciprocable thereon, a work spindle on the carriage adapted to support a gear blank thereon, means for reciprocating the carriage, a tool disposed in the path Vof movement of the blank on the carriage,

means for indexin said blank with res ect to the tool at a pre etermined position o the carriage, said means including a rack, a pinion meshing therewith, means for moving the rack longitudinally in timed relation to the movement of the carriage, a ratchet wheel on the spindle, a pawl therefor, and gear connections between the pawl and the pinion.

23. In a gear grinding machine, a main frame, a planulur faced rotary grinding wheel, a carriage reciprocable on the frame, means for reciprocating the carriage, a work spindle on the carriage adapted to support a gear blank thereon, a master rack, a master gear on the work spindle adapted to mesh with and roll upon the rack, a rack support on the frame below the 'rack for supporting it and vertically movable on the frame for adj stably moving the rack upwardly toward and downwardly away from the master gear.

In testimony whereof I hereuntopaliix my signature this 12th day of August, 1925.

CHARLES H. SCHURR. 

